The present invention relates in general to image displays and more specifically to apparatus for removing irrelevant background information and for adjusting image brightness and contrast according to statistical information of the image.
The various applications of video displays and of hard-copy presentation of images have increased as computer graphics capabilities have improved. In an interactive graphics system, a processor creates a display file according to instructions from an operator. In one common arrangement, a displayed image consists of a plurality of pixels arranged in columns and rows. The display file consists of a magnitude for each pixel. In displaying an image, the operator can specify certain image parameters, such as image brightness and/or contrast.
Adjustment of such parameters may be critical in many applications to best visualize certain aspects of the data in the image. For example, in medical diagnostic imaging modalities, such as x-ray, nuclear medicine, computed tomography (CT), and nuclear magnetic resonance (NMR), optimum brightness and contrast varies according to the objective or specific parameters of an imaging experiment, and according to operator preference.
It is typically inconvenient and time consuming to adjust each image in a series of images taken by an operator. In addition to presenting an image to the operator during an image experiment (usually on a cathode ray tube), it is often desired to transfer images to film or to other permanent record. However, inefficiency results if the operator is required to adjust each new image during a series of experiments and filming operations to best visualize the information being sought.
A further problem in presenting an optimum image on a graphics display relates to the significance of a background in the image in relation to the region of interest. For example, where a background exists, it may contribute noise to the image which interferes with presentation of the region of interest.
Accordingly, it is a principal object of the present invention to provide graphics apparatus having improved image presentation.
It is another object of the invention to provide consistent image presentation over a series of images.
It is a further object of the invention to reduce the impact of image background on presentation of the region of interest.
It is yet another object of the invention to improve operator efficiency in medical diagnostic imaging experiments.